Derfred,
I used to practice them for fun on the 747 simulator. I forget the glide angles with various stages of flap and with and without gear down, but one way of modifying the glide angle was to use sideslip, it worked in the simulator but I don't know how much could be used safely on the real aircraft. The other way of adjusting height to touchdown was to use a turning approach where you could cut the corner or tighten the turn as necessary and, for obvious reasons, taking great care to control the speed well above the stall.